2
DEMO MANUAL DC1811B-B
Rev. A
QUICK START PROCEDURE
PERFORMANCE SUMMARY
(T
A
= 25°C)
PARAMETER
CONDITION
VALUE
Input Voltage Range
4.5V to 26.5V
Output Voltage, V
OUT0
V
IN
= 4.5V to 26.5V, I
OUT0
= 0A to 13A
0.5V to 5.5V (Minimum On)*, Default: 1V
Maximum Output Current, I
OUT0
V
IN
= 4.5V to 26.5V, V
OUT
= 0.5V to 5.5V
13A
Output Voltage, V
OUT1
V
IN
= 4.5V to 26.5V, I
OUT1
= 0A to 13A
0.5V to 5.5V (Minimum On)*, Default: 1.8V
Maximum Output Current, I
OUT1
V
IN
= 4.5V to 26.5V, V
OUT
= 0.5V to 5.5V
13A
Typical Efficiency
V
IN
= 12V, V
OUT
= 1.8V, I
OUT
= 13A
86.3%
Default Switching Frequency
500kHz
*For low duty cycle applications, it may approach minimum on the limit. The minimum on-time for LTM4676A is 45ns nominal, guardband to 90ns.
Demonstration circuit 1811B-B is easy to set up to evalu-
ate the performance of the LTM4676A. Refer to Figure 2
for the proper measurement equipment setup and follow
the procedure below.
1. With power off, connect the input power supply to V
IN
(4.5V to 26.5V) and GND (input return).
2. Connect the 1.0V output load between V
OUT0
and GND
(Initial load: no load).
3. Connect the 1.8V output load between V
OUT1
and GND
(Initial load: no load).
4. Connect the DVMs to the input and outputs. Set default
jumper position: JP1: ON; JP2: ON.
5. Turn on the input power supply and check for the
proper output voltages. V
OUT0
should be 1.0V ±0.5 %,
and V
OUT1
should be 1.8V ±0.5%.
6. Once the proper output voltages are established, adjust the
loads within the operating range and observe the output
voltage regulation, ripple voltage and other parameters.
7. Connect the dongle and control the output voltages
from the GUI. See “LTpowerPlay GUI for the LTM4676A
Quick Start Guide” for details.
Note: When measuring the output or input voltage rip-
ple, do not use the long ground lead on the oscilloscope
probe. See Figure 3 for the proper scope probe technique.
Short, stiff leads need to be soldered to the (+) and (–)
terminals of an output capacitor. The probe’s ground ring
needs to touch the (–) lead and the probe tip needs to
touch the (+) lead.
Connecting a PC to DC1811B-B
You can use a PC to reconfigure the power management
features of the LTM4676A such as: nominal V
OUT
, mar-
gin set points, OV/UV limits, temperature fault limits,
sequencing parameters, the fault log, fault responses,
GPIOs and other functionality. The DC1613A dongle may
be plugged when V
IN
is present.
Table 1. LTM4676/LTM4676A Demo Cards for Up to 130A Point-of-Load Regulation
MAXIMUM OUTPUT CURRENT
NUMBER OF OUTPUT VOLTAGES
NUMBER OF LTM4676/LTM4676A µMODULE
REGULATORS ON THE BOARD
DEMO BOARD NUMBER
13A, 13A
2
1× LTM4676
DC1811A/DC1811B-A
13A, 13A
2
1× LTM4676A
DC1811B-B
26A
1
1× LTM4676
DC2087A
50A
1
2× LTM4676
DC1989A-A
75A
1
3× LTM4676
DC1989A-B
100A
1
4× LTM4676
DC1989A-C
100A
1
1× LTM4676 (+ 3× LTM4620A)
DC2106A-A
130A
1
1× LTM4676 (+ 3× LTM4630)
DC2106A-B
